The landmarked home is located at 39 East 72nd Street and sold last week for just over $19 million. The Mangold family sold the five-floor asset to the group of investors who will redevelop it as floor-through condos. The trio includes three KWNYC brokers, a residential brokerage: Ilan Bracha, Haim Binstock and Daniel Minkowitz. Messrs. Bracha and Binstock’s B+B Capital partnered with Mr. Minkowitz’s Mink Development on the project, which is not affiliated with KWNYC, according to a representative for the developers.

“We are the mystery buyer,” Mr. Bracha confirmed to Mortgage Observer. The transaction included air rights and the triad intends to build with “very high end finishes.” He added that the development would be the “perfect fit for the neighborhood.”

Madison locked down the deal because they were able to close swiftly, Josh Zegen, co-founder of Madison, told Mortgage Observer. The one-year loan has two options to extend and was arranged in three weeks. Mr. Zegen declined to give the rate of the mortgage, which closed April 11, but said Madison typically charges “8 to 12 percent and one to three origination points.”

The 14,000-square-foot home had sat on the market since 2005, according to our report last week. Mr. Bracha confirmed that the closing price was just over $19 million, though the digs were last listed asking $21.5 million.

Originally home to heiress, philanthropist and mom to Anderson Cooper Gloria Vanderbilt, the home had been occupied by a Daniel Mangold most recently, sources told NYO.